Limitations of food composition data References Vitamin D

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Limitations of food composition data References Vitamin D
Liver and Vitamin D: fact or fiction?
Liz Williams, Renee Sobolewski, David Fraser
Food Standards Australia New Zealand, Canberra, ACT, 2610, Australia
Introduction
Limitations of food composition data
Table 1 Vitamin D Content in Food (9)
Liver is commonly reported as a good source of vitamin D in the diet. However, liver from
terrestrial animals contains very little vitamin D as a result of hepatic catabolism. Fish liver, by
contrast is a good source of vitamin D as the fatty acid ester is stored in the liver fat of fish.
AUSNUT 2007 contains the best available data for vitamin D concentrations in foods in
Natural Sources
AUSNUT 2007 is a nutrient database that was developed for estimating nutrient intakes from
food, beverages and dietary supplements consumed as part of the 2007 National Children’s
Nutrition and Physical Activity survey (Kids Eat, Kids Play).
µg per 100g food
Australia, although the dataset is based on only a small set of Australian analyses. Wherever
analytical data was unavailable the most reasonable data for the foods where it was likely to
make a difference to nutrient intakes was obtained. For this reason, the vitamin D data should
AUSNUT 2007 contains Australia’s most comprehensive vitamin D dataset (1). The vitamin
D dataset is a combination of Australian analytical data and where Australian data were not
available, data has been derived using established data compilation techniques such as
borrowed data from overseas food composition tables and imputation.
Challenges with developing a Vitamin D
database for foods
Two forms of vitamin D are found in foods, cholecalciferol (D3) and ergocalciferol (D2).
Vitamin D3 is the more widely distributed (e.g. in fish oils, fatty fish tissues, eggs, butter) and
D2 occurs naturally in foods such as mushrooms (2). Estimates of the relative activities of
cholecalciferol, ergocalciferol and their metabolites (25-hydroxycholecalciferol) vary.
Vitamin D in foods is found at a very low concentration, which makes its analysis difficult.
Also, most food sources contain other lipids that tend to interfere with the analysis (3).
Analysing different forms of vitamin D requires validated analytical methods and reference
materials for vitamin D. Existing analytical methods have lacked specificity, sensitivity and
precision. Developing a comprehensive analytical program for generating vitamin D data that
are representative of the national food supply is costly because the chemistry is complex,
food sampling and preparation is expensive, and compiling and estimating values is time
consuming and detailed work (4).
Data origin
Beef fillet, grilled
Australian analysis
0.1
Cheese, cheddar
Australian analysis
3.32
Chicken breast, grilled
Australian analysis
0.12
Cod liver oil
Borrowed (UK)
210
Egg
Australian analysis
0.9
composition (e.g. the cultivar of a plant that is selected) and also factors associated with
Liver, chicken, fried
Australian analysis
0.27
variability in production, formulation and storage practices (14). Also the limitations associated
Milk, regular fat
Australian analysis
0.52
Salmon Atlantic, fillet, grilled
Australian analysis
7.4
still be interpreted with caution.
In general, there will always be limitations with food composition data. Nutrient data should
be regarded as approximations of the likely nutrient content of the food, beverage and
supplement to which they refer. This is because the nutrient composition of foods is
variable and dependent on a range of factors. There are inherent factors affecting nutrient
with method of analysis should be considered and are particularly relevant for vitamin
D. There is also some debate about the appropriate bioavailability factors to use when
estimating total vitamin D activity in a food from the different forms of the vitamin that may be
present (15).
Fortified Foods
Data origin
µg per 100g food
Margarine spreads
Australian analysis
4.5
Milk, reduced fat, fortified
Label
2.24
Yoghurt, extra creamy, fortified
Label
1.51
References
1. Food Standards Australia New Zealand. (2007). Australian Food,
Supplement & Nutrient Database 2007 for estimation of population nutrient intakes. Explanatory Notes.
2. Greenfield, H. And Southgate, DAT. (2003). Food composition data.
Production, management and use, pp. 129-131. Rome, FAO.
Vitamin D fortification
3. Ball, GFM. (1998). Bioavailability and analysis of vitamins in foods.
London, Chapman and Hall.
Fortification of foods traces back to the need to address vitamin deficiencies. Various
4. Holden, J.M. and Lemar, LE. (2008). Assessing vitamin D contents in foods
and supplements: challenges and needs. Am J Clin Nutr 2008:88(suppl):551S-3S.
Vitamin D intakes in the KEKP Survey 2007
diseases such as rickets can be linked to the lack of vitamin D. Vitamin D is also known
The estimated intakes for vitamin D were less than the adequate intakes (AIs) of 5 µg/day
(5). Whilst these findings may suggest that a significant number of children may not be
consuming sufficient vitamin D, a definitive conclusion cannot be reached. Vitamin D experts
have reported that between 80-100% of our vitamin D is sourced from casual exposure to
sunlight. However there is increasing recognition that a significant number of Australians and
people from specific groups within the community are at risk of vitamin D deficiency (6).
society, many people have reduced sun exposure due to spending a large amount of time
many people on a daily basis. Refer to Table 2 for a comparison of the range of foods fortified
7. 2007 Australian National Children’s Nutrition and Physical Activity Survey –
Main Findings. Publications Number: P3-4592, Commonwealth of Australia, Canberra.
Graph 1 Mean intake of vitamin D by age group and gender, KEKP2007 (7)
with vitamin D in differing countries.
8. Kids Eat Kids Play Survey. (2007). Food Standards Australia New Zealand, Canberra.
Table 2 Comparisons of vitamin D fortification in Australia, US and the UK (11,12,13)
9. Food Standards Australia New Zealand (2007). AUSNUT 2007 –
Australian Food Composition Tables. Canberra: FSANZ.
as the “Sunshine Vitamin”, as it is produced in the skin by exposure to sunlight. In today’s
indoors, wearing sunscreen when outdoors or wearing fully protective clothing, thereby
reducing formation of this vitamin (10). Vitamin D is not present in many foods that we
consume on a daily basis, so it was decided decades ago to fortify certain foods with this
vitamin. In Australia margarine was considered an appropriate choice, as it is consumed by
µg of vitamin D per day
4.5
4
Mandatory Fortification
with Vitamin D
3.5
3
2.5
Boys
2
1.5
Girls
Total Children
1
Australia
Margarines & oil spreads
0.5
0
2-3 years
4-8 years
9-13 years
14-16 years
Age in years
The Kids Eat Kids Play survey revealed that liver and liver containing products contributed
only 0.02 % of the total vitamin D intake among survey participants. Margarine spreads
contributed 4.3 % of the total vitamin D intake (8). This was due to the combined effect of
the fortified levels of vitamin D in margarines and that they are widely consumed. Other major
contributors were dairy milks (27.7%), multivitamin supplements (13.3%) and cheese (12.2%).
Table 1 lists the vitamin D content of a number of foods as reported in AUSNUT 2007.
Australia New Zealand PO Box 7186 Canberra BC ACT 2610 PO Box 10559 The Terrace Wellington 6036 Dried milks
Modified milks & skim milk
Cheese & cheese products
Yoghurts
Dairy Desserts
Butter
Milk & milk products
Breakfast cereals
Baked goods
Margarine and spreads
Orange juice
Soy products
United States
United Kingdom
Voluntary Fortification with
Vitamin D
Margarine
Other spreads
Breakfast cereals
www.foodstandards.gov.au
www.foodstandards.govt.nz
5. National Health and Medical Research Council. (2006) Nutrient Reference Values
for Australia and New Zealand. Canberra.
6. Holick, M. (2001). Sunlight “D”ilemma: risk of skin cancer or bone disease
and muscle weakness. Lancet 2001;357:4-6.
10. Nowson, CA, Diamond, TH, et al. Vitamin D in Australia. Issues and Recommendations. (2004). Australian Family Physician 33;133-138.
11. Food Standards Australia New Zealand.
http://www.foodstandards.gov.au
12. United States Department of Agriculture.
http://www.usda.gov
13. United Kingdom Food Standards Agency
www.food.gov.uk
14. Pennington, JAT (2008). Applications of food composition data: Data sources and consideration for use. J Food Composition & Analysis, 21:S3-S21.
15. Valverde, J, Hayes M. (2010). EuroFoodChem XV: food for the future.
The contribution of chemistry to improvement of food quality.
Eur Food Res Technol 2010 230:687–691.

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